Denture.



R. M. CRAIG. DENTUREL APPLICATION man 050.11.1914.

Patented Apr. 3,1917.

WITNESSES:

barman snares parent oration.

RoBER'r MEADE CRAIG, or wILKINsBURe, PENNSYLVANIA.

DEN'IURE.

Specification of Letters Patent.

Patented Apr. 3, 1917.

Application filed December 11, 1914. Serial No. 876,665.

To all whom it may concern:

Be it known that I, ROBERT Manon CRAIG, a citizen of the United States, residing at Wilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a certain new and useful Improvement in Dentures, whereof the following is a specification, reference being had to the accompanying drawing.

My improvement relates to a metallic backing for a porcelain tooth facing, which may be utilized in a plate, bridge, or other form of denture, and of the class contemplated in Letters Patent of the United States 12,753 reissued to me February 18, 1908. I found in practice that it was necessary to carry in stock a large number of sizes of backings, if made in a single piece, and, as said backings are usually made of gold, a very large amount of that metal was thus necessarily held without any income from,

the investment therein. Therefore, the principal object of the present invention is to avoid the necessity for such an idle invest ment, by the provision of backing elements which are adapted for porcelain facings of different sizes, so as to minimize the amount of gold necessary to carry in stock.

As hereinafter described, my invention includes the provision of pairs of oppositely flanged and substantially similar backing members, adapted to be united by a fusible element, which thereafter-holds them in apposed relation to engage a porcelain facing between them; the variation in the size of the backing being compensated by more or less of the fusible element.

Moreover, such dentures are so constructed and arranged that the porcelain may be readily removed from the metal, without removing the latter from its setting, and in said Letters Patent, I showed a locking device including a metallic key extending through an opening in the backing into a recess in the porcelain, which key it is necessary to remove in order to remove the porcelain from the backing. Therefore, a further object of my present invention is to dispense with said key and employ in lieu thereof a portion of the backing in unitary relation with the latter at the end thereof re mote from the jaw.

My invention includes the various novel features of construction and arrangement hereinafter more definitely specified.

.In the drawings; Figure I is a plan view of a denture representing an incisor tooth.

Fig. II is a front elevation of said incisor denture.

F ig. III is a left side elevation of said incisor denture.

Fig. IV is a rear elevation of denture.

Fig. V is a plan view of a denture representing a bicuspid tooth.

Fig. VI isa front elevation of said bicuspid denture.

Fig. VII is a left side elevation of said bicuspid denture.

Fig. VIII is a rear elevation of said hicuspid denture.

Fig. IX is a perspective view of one member of the pair of the incisor backing members shown united in Figs. I to IV inclusive.

Fig. X is a perspective view of one member of the pair of bicuspid backing members shown united in Figs. V to VIII inclusive.

Referring to Figs. I to IV inclusive; the porcelain body comprises the anterior portion 1 and the posterior portion 2 in unitary relation. Said anterior portion forms a facing which may be of any desired size, representing a natural tooth, and said posterior portion forms a dovetail whereby said body is supported in and engaged by the metallic backing 3, which may form part of a plate, bridge or other denture. As indicated by the dotted lines in Figs. II, III and IV, said dovetail 2 is wedge shaped in two directions at right angles to each other, its side faces converging both from its occlusal or incisal end 4: to its gingival end 5 and from its lingual side 6 to its labial or buccal side 7, where it merges into the anterior portion 1 of said body; said converging surfaces being symmetrically disposed with respect to the central vertical plane of the porcelain body. Said posterior dovetail portion 2 is also converged and concavely curved longisaid incisor tudinally in its lingual face from its gingival end toward its incisal end as best shown at 9 in Fig. III. Said posterior portion 2 of said porcelain body being converged in three directions, as above described, is fitted in a correspondingly shaped recess in the metallic backing 3, the exterior contour of which resembles that of the tooth imitated by the anterior portion 1 of said porcelain body.

It may be observed that the construction and arrangement above described is such that the strains to which the denture is normally subjected, viz., pressure in a direction from its incisal or occlusal end toward its gingival end, and transversely from its linual to its labial side, merely serve to more firmly seat said porcelain body in its backing 3. Although there is no normal strain upon the denture tending to remove said porcelain body from its metallic backing in the direction from its gingival end to its occlusal end, it may be manually slid and removed. in that direction, without removing the backing from its setting, whenever it is desired to renew the porcelain body, and, although it is unnecessary to provide any special means for preventing such sliding movement, in addition to the frictional engagement between said body and its backing, they may be cemented in connection with each other, and I. prefer to provide said backing 3 with the unitary locking flange 11 at its end remote from the jaw, normally preventing said body from thus sliding; whereby it is necessary to bend said locking flange to remove said body. Of course, said locking flange may be rebent to engage the porcelain body when it is replaced.

Said metallic backing 3 comprises apposed and substantially oppositely counterpart backing members 13 and 14 which are flanged in complementary relation with said porcelain body and united atthe lingual face thereof by the fusible element 16 which is of greater or less width in accordance with the size of the tooth to be imitated; all sizes of porcelain bodies for a given tooth being conveniently recessed alike to receive said backing members 13 and 14, so that only one pattern of such members need be carried in stock for each of the natural teeth to be imi-;

tated.

Although I have referred to the filling piece 16, which unites the apposed backing members 13 and 14 as a fusible element, it is to. be understood that a suitable filling piece may be made of a strip of gold or other metal and soldered or autogenously welded to said backing members only at its junctions with the latter.

Referring to Figs. V to VIII inclusive;

the porcelain body comprises the anterior portion 18 and the posterior portion 19 in unitary relation. Said anterior portion forms a facing which may be of any desired size, representing a natural biscupid tooth, and said posterior portion forms a dovetail whereby said body is supported in and engaged by the metallic backing 20, which may form part of the plate, bridge or other denture. As indicated by the dotted lines in Figs. V, VI and VIII, said dovetail 19 is wedge shaped in two directions at right angles to each other, its side faces converging both from its occlusal end 21 to its gingival end 23 and from its lingual side 2 1 to its buccal side 25 where it merges into the anterior portion 18 of said body; said converging surfaces being symmetrically disposed with respect to the central vertical plane of the porcelain body. Said posterior dovetail portion 19 is also converged and concavely curved longitudinally at its lingual side, from its gingival end toward its occlusal end as best shown at 27 in Fig. VII. Said posterior portion 19 of said porcelain body being converged in three directions, as above described, is fitted in a correspondingly shaped recess in the metallic backing 20, the exterior contour of which resembles that of the bicuspid tooth imitated by the anterior portion 18 of said porcelain body.

Said metallic backing 20 comprises apposed and substantially oppositely counterpart backing members 28 and 29 which are flanged in complementary relation with said porcelain body and united at the lingual face thereof by the fusible element 30 which is of greater or less width in accordance with the size of the tooth to be imitated, as above set forth.

I do not desire to limit myself to the specific details of construction and arrangement herein set forth as it is obvious that various modifications may be made therein without departing from the essential features of my invention as defined in the appended claims.

I claim 1. In a denture, the combination with a porcelain body having a wedge shaped portion converging both from its occlusal end towardits gingival end and from its lingual side toward its labial side; of a metallic backing having flanges complementary to the wedge shaped portion of said body and engaged therewith; said backing comprising a pair of primarily separate substantially similar apposed members, united by a fusible element between them whereby the parts united are made larger; the interengaged portions of said body and backing being so constructed and arranged that said body may, if not otherwise prevented, be slid from said backing in the direction from its gingi val end to its occlusal end, but not in the opposite direction; and a locking flange, in unitary relation with said backing, at the end of said backing remote from the jaw normally preventing said body from thus sliding; whereby it is'necessary to bend said locking flange to remove said body.

2. In a denture, the combination with a porcelain body having a wedge shaped portion converging both from its occlusal and toward its gingival end and from its lingual side toward its labialside; of a metallic backing havingflanges complementary to the wedge shaped portion of said body and engaged therewith; said backing comprising a pair of primarily separate apposed members, united by a fusible element between them whereby the parts united are made larger; the interengag'ed portions of said body and backing being so constructed and arranged that said body may, if not otherwise prevented, be slid from said backing in the direction from its gingival end to its occlusal end, but not in the opposite direction; and a locking element at the end of said backing remote from the j aw normally preventing said body from thus sliding; whereby it is necessary to bend said locking element to remove said body.

3. In a denture, the combination with a porcelain body having a wedge shaped portion converging from its occlusal end toward its gingival end; of a metallic backing having flanges complementary to the wedge shaped portion of said body and engaged therewith; said backing comprising a pair of apposed members, united by a fusible element between them whereby the parts united are made larger; the interengaged portions of said body and backing being so constructed and spaced that said body may beslid from said backing in the direction fromits gingival end to its occlusal end, but not in the opposite direction.

4c. In a denture, the combination with a porcelain body having a wedge shaped portion converging from its lingual side toward its labial side; of a metallic backing having flanges complementary to the wedge shaped portion of said body and engaged therewith; said backing comprising a pair of apposed members, united by a fusible element between them whereby the parts united are made larger; the interengaged portions of said body and backing being so constructed and spaced that said body may he slid. from said backing in the direction from its gingival end to its occlusal end, but not in the opposite direction.

5. In a denture, the combination with a porcelain body having a wedge shaped portion converging from its lingual side toward its labial side; of a metallic backing having flanges complementary to the wedge shaped portion of said body and engaged therewith; said backing comprising a pair of apposed members, united by a primarily separate ele ment between them whereby the parts united are made larger; the interengaged portions of said body and backing being so constructed and spaced that said body may be slid from said backing in the direction from its gingival end to its occlusal end, but not inthe opposite direction.

6. In a denture, the combination with a porcelain body having undercut recesses; of a metallic backing having flanges complementary to recesses of said body and en gaged therewith; said backing comprising a pair of substantially similar primarily sepa rate apposed members, united by a fusible element between them whereby the parts united are made larger; the interengaged portions of said body and backing being so constructed and spaced that said body may he slid from said backing in the direction from its gingival end to its occlusal end, but not in the opposite direction.

7. In a denture, the combination with a porcelain body; of a metallic backing complementary to said body and engaged therewith, to form the configuration of a natural tooth; said backing comprising a pair of ap posed members, united by a fusible element between them whereby the parts united are made larger.

8. In a denture, the combination with a porcelain body; of a metallic backing complementary to said body and engaged therewith, to form the configuration of a natural tooth; said backing comprising a pair of apposed members, united by another element between them whereby the parts united are made larger.

9. In a denture, the combination with a porcelain body; of a metallic backing complementary to said body and engaged therewith, to form the configuration of a natural tooth; said backing comprising a pair of apposed members, spaced and arranged to embrace said body between them, united by another element between them, whereby the parts united are made larger and having a bendable locking flange, in unitary relation therewith, arranged to engage said porcelain bod 13 An article of manufacture, element of a denture adapted ultimately to support a non-metallic tooth body; said article being a piece of metal having the outer configuration of a perimetral portion of a natural tooth, and adapted to be connected to an apposed complementary metallic article, to embrace and hold said non-metallic body 'between them; said article having a member Whichis bendable to release said body, for repalrs, after such connectlon, Without disconnectlon of said complementary metallic articles.

11. An article of manufacture, element of a denture adapted ultimately to support a non-metallic tooth body; said article being a piece of metal having the outer configuration of a perimetral portion of a natural 10 tooth, and adapted to be connectedto an apfi opies of this patent may be obtained for five cents each, by addressing the "Commissioner of Yatenta Washington, D. G." 

